1980 Dodge w150 questions

Just picked up a new to me 1980 dodge ram power wagon w150. Has a 318 and a 3sp with overdrive. Has about a 3" lift I think. Have several questions
The speedometer is very funky. It will get stuck in random places on the gauge. Will this require a new speedo or cable or both? Where is the cable attached to the trans?
It has an aftermarket radio shoved into the dash to the right of the steering wheel. It's not bolted done or anything. Is there a bracket that I can install to mount the radio?
What are some common upgrades to get more power?
Intake mani and 4bbl carb? How much power does an intake and carb swap make? Anything else?

Just picked up an Edelbrock Performer 4bbl intake manifold. Part # 3776. What would be a good carb that won't brake the bank? The current set up has a manual choke. Looking for a simple swap. And would a 1" carb spacer be worth it?

From what I've read about the 318 is a 550-600cfm carb would be good for street and 700+ for racing. This is mainly a back and forth to work truck. And some mild off roading and playing in some mud. Would like to get it into the 300hp mark. Thinking some cleaned up heads, mild cam and exhaust. Longtubes and duals. Undecided on mufflers

300hp would be quite a bit of work as the stock LA 318 only makes around 180hp stock. I would be going for torque, personally. If you're going to pull the engine, freshen it up and perform the work you speak of.

Hell, if you're looking to spend that much money you might look at swapping in a Magnum 318 and carb it instead. At the very minimum I'd be looking at aftermarket heads to replace the factory SMOG heads on the current 318.

you may want to do your own research on the subject since some other disagree with me on it but anything over 500cfm on a small little 318 is too much. the cfm calculator on summits website says a 318 with a max engine rpm of 5000 would need a 391.06cfm for street use or 506.08 for racing
this kind of explain the difference between street engine and race enginehttp://www.summitracing.com/popup/ca...cfm-calculator

Quote:

The ratings are different because street engines have a volumetric efficiency around 85% while racing engines are closer to 110%.

If I pull the engine I'm going to put something else in. The moror/trans were installed 2 years ago. It had an auto stock. So what would some realistic numbers be with a 500cfm 4bbl carb, headers and exhaust and a mild cam be? And where can I find out what trans I have? All I know is its a 4sp manual. 1st is a granny gear and 4th is overdrive. Also have no idea what gears are installed. And the tcase is an np208. Thanks for the replies